^[A] Paula Abdul served as a guest judge for London Auditions.
^[B] Brian Friedman served as a guest judge for the London auditions, but was re-assigned the role of creative director and was replaced by former judge Louis Walsh. He was originally recruited to be a permanent judge.
^[C] During the auditions and bootcamp, several guest judges served as temporary replacement for Dannii Minogue, who was not able to attend due to being pregnant. Geri Halliwell served as guest judge at the Glasgow auditions; Natalie Imbruglia at the Birmingham auditions; Katy Perry at the Dublin auditions; Pixie Lott at the Cardiff auditions; and Nicole Scherzinger at the Manchester auditions and bootcamp.
